dhcpcd-6.8.2: Change vendor_encapsulated_options to binhex
This is the same CL as https://chromium-review.googlesource.com/#/c/320426/ and
is applied here to work correctly on Brillo
Make option vendor_encapsulated_options of type binhex and pass
VendorEncapsulatedOptions on dbus as a byte array
BUG: chromium:574578
TEST=run `dbus-monitor --system \
"type=signal,path=/org/chromium/dhcpcd,interface=org.chromium.dhcpcd,arg1='BOUND'"`
and check that VendorEncapsulatedOptions is sent as array of bytes
Change-Id: Icd9c6c1f73d5eb46a8eb04204e6d2cb039a38f45